PIP: 43 determinants of low birth weight were analyzed from 895 published papers in the English and French literature from 1970-1984 The assessment was limited to singleton births of women living at sea level with no chronic illness; rare factors and complications of pregnancy were excluded The 43 factors were categorized as genetic and constitutional, demographic and psychosocial, obstetric, nutritional, maternal morbidity during pregnancy, toxic exposure and antenatal care The existence and magnitude of a causal effect on birth weight, gestational age, prematurity and intrauterine growth retardation were determined by a set of methodological standards In developed countries, the most important factor was cigarette smoking, followed by nutrition and pre-pregnancy weight In developing countries the major determinants were racial origin, nutrition, low pre-pregnancy weight, short maternal stature, and malaria Pre-pregnancy weight, prior premature birth or miscarriage, diethylstilbestrol exposure and smoking were major determinants of gestational duration, but the majority of prematurity was unexplained in both developed and developing countries There is a need for future research on the effect of maternal work, prenatal care, and certain vitamin and mineral deficiencies on intrauterine growth, and the effect of genital tract infection, prenatal care, maternal employment, stress and anxiety on prematurity

Determinants of low birth weight: Methodological assessment and meta-analysis

For a current, practical introduction to the field of sampling that you'll want to keep close at hand, Sharon L. Lohr's SAMPLING: DESIGN AND ANALYSIS, 2ND EDITION, answers the call. Practical and authoritative, the book is listed as a standard reference for training on real-world survey problems by a number of prominent surveying organizations. Lohr concentrates on the statistical aspects of taking and analyzing a sample, incorporating a multitude of applications from a variety of disciplines. The text gives guidance on how to tell when a sample is valid or not, and how to design and analyze many different forms of sample surveys. Recent research on theoretical and applied aspects of sampling is included, as well as technology instructions for using statistical software with survey data.

Sampling: Design and Analysis

Sponsors asked the IOM's Food and Nutrition Board and the Division of Behavioral and Social Sciences and Education Board on Children, Youth, and Families to review and update the IOM (1990) recommendations for weight gain during pregnancy and recommend ways to encourage their adoption through consumer education, strategies to assist practitioners, and public health strategies.The committee was asked to address the following tasks: 1. Review evidence on the relationship between weight gain patterns before, during, and after pregnancy and maternal and child health outcomes, with particular attention to the prevalence of maternal obesity racial/ethnic and age differences, components of GWG, and implications of weight during pregnancy on postpartum weight retention, maternal and child obesity, and later child health. 2. Within a life-stage framework consider factors in relation to GWG that are associated with maternal health outcomes such as lactation performance, postpartum weight retention, cardiovascular disease, metabolic processes including glucose and insulin-related issues, and risk of other chronic diseases; for infants and children, in addition to low birth weight, consider early developmental impacts and obesity-related consequences (e.g., mental health, diabetes). 3. Recommend revisions to the existing guidelines, where necessary, including the need for specific pregnancy weight guidelines for underweight, normal weight, and overweight and obese women and adolescents and women carrying twins or higher-order multiples. 4. Consider a range of approaches to promote appropriate weight gain, including: individual (behavior), psychosocial, community, health care, and health systems; timing and components of interventions; and ways to enhance awareness and adoption of the guidelines, including interdisciplinary approaches, consumer education to men and women, strategies to assist practitioners to use the guidelines, and public health strategies. 5. Identify gaps in knowledge and recommend research priorities.

/pdf/weight-gain-during-pregnancy-reexamining-the-guidelines-54naat6auf.pdf

Weight Gain During Pregnancy: Reexamining the Guidelines

The "fetal" or "early" origins of adult disease hypothesis was originally put forward by David Barker and colleagues and stated that environmental factors, particularly nutrition, act in early life to program the risks for adverse health outcomes in adult life. This hypothesis has been supported by a worldwide series of epidemiological studies that have provided evidence for the association between the perturbation of the early nutritional environment and the major risk factors (hypertension, insulin resistance, and obesity) for cardiovascular disease, diabetes, and the metabolic syndrome in adult life. It is also clear from experimental studies that a range of molecular, cellular, metabolic, neuroendocrine, and physiological adaptations to changes in the early nutritional environment result in a permanent alteration of the developmental pattern of cellular proliferation and differentiation in key tissue and organ systems that result in pathological consequences in adult life. This review focuses on those experimental studies that have investigated the critical windows during which perturbations of the intrauterine environment have major effects, the nature of the epigenetic, structural, and functional adaptive responses which result in a permanent programming of cardiovascular and metabolic function, and the role of the interaction between the pre- and postnatal environment in determining final health outcomes.

https://www.physiology.org/doi/pdf/10.1152/physrev.00053.2003

Developmental Origins of the Metabolic Syndrome: Prediction, Plasticity, and Programming

Obstetrics and gynecology.

This randomized controlled trial of nutritional supplementation in pregnancy, in a poor black urban population in the United States, aimed to increase the birth weight and influence the postnatal development of the offspring of mothers at high risk of having low birth weight infants. The execution of the research design and adherence to the treatment regimen among the experimental population appeared adequate for a reasonable test of the treatments. At birth, the only significant favorable effect of supplementation observed was the prevention of depressed birth weight among the offspring of mothers who smoked heavily. With balanced protein-calorie supplementation, length of gestation was increased, the proportion of low-birth-weight infants reduced, and mean birth weight raised by 41 gm (not statistically significant). With high protein supplementation, there was an excess of very early premature births and associated neonatal deaths, and there was significant growth retardation up to 37 weeks of gestation. At 1 year of age, significant effects of high protein supplement were found on three psychological measures: visual habituation, visual dishabituation, and mean length of free play episodes. These measures were unrelated to measures of growth at birth and at 1 year of age. There were no detectable residual adverse effects of high protein supplementation at 1 year of age.

A Randomized Controlled Trial of Prenatal Nutritional Supplementation in New York City

Ongoing surveys performed by Ross Laboratories demonstrate recent declines both in the initiation of breast-feeding and continued breast-feeding at 6 months of age Comparing rates in 1984 and 1989, the initiation of breast-feeding declined approximately 13% (from 597% to 522%), and there was a 24% decline in the rate of breast-feeding at 6 months of age (from 238% to 181%) The decline in breast-feeding was seen across all groups studied but was greater in some groups than in others Logistic regression analysis indicates that white ethnicity, some college education, increased maternal age, and having an infant of normal birth weight were all positively associated with the likelihood of both initiating breast-feeding and continuing to breast-feed to at least 6 months of age Women who were black and who were younger, no more than high school educated, enrolled in the Women, Infants and Children supplemental food program, working outside the home, not living in the western states, and who had an infant of low birth weight were less likely either to initiate breast-feeding or to be nursing when their children were 6 months of age The factors influencing the decline in breast-feeding were not uniform There were fewer sociodemographic factors associated with the decline in the initiation of breast-feeding than in the decline in prolonged breast-feeding While the disparity between older and younger mothers in initiating breast-feeding increased, there was an offsetting trend as the disparity associated with parity decreased(ABSTRACT TRUNCATED AT 250 WORDS)

Recent Declines in Breast-Feeding in the United States, 1984 Through 1989

Examination of the relationship between birthweight, cigarette smoking during pregnancy and maternal weight gain

A prospective study of pregnant patients of a Boston hospital was undertaken in 1961-1962 to assess the relationship of smoking with perinatal mortality and with other differences found in the study population of 490 white and 530 black women. The analysis of perinatal mortality was heightened by the addition of data on 2256 additional patients who fulfilled the same criteria as the study population. More than twice as many whites smoked cigarettes than blacks. White multigravidae who experienced a loss of the observed pregnancy had a history of excessive loss (34.2%) which was accentuated among the smokers (52.8%). Birth weights were higher in whites and nonsmokers and rose linearly with time for gestation over 40 weeks in nonsmokers whereas diminished birth weights were associated with long gestation in smokers. The average length of gestation among blacks was substantially lower than among whites and whites had higher hematocrits. Social differences including place of birth and marital status were found between smokers and nonsmokers but differences in birth weights were not related to social factors. Perinatal mortality was almost double among black smokers with loss occurring frequently early in pregnancy. The stillbirth/neonatal death ratio was found to be independent of race smoking or parity. A review of the English language literature shows an impressive association between maternal smoking and perinatal loss when the figures are aggregated. As would be expected this loss is greater among women of lower socioeconomic status where differences may be accentuated (as they may also be in late pregnancy).

David Rush

Papers

A Randomized Controlled Trial of Prenatal Nutritional Supplementation in New York City

Recent Declines in Breast-Feeding in the United States, 1984 Through 1989

Examination of the relationship between birthweight, cigarette smoking during pregnancy and maternal weight gain

Maternal smoking: a reassessment of the association with perinatal mortality

Antecedents of Low Birthweight in Harlem, New York City